Ball grid array packages

Abstract: A BGA carrier for storing and shipping of BGA packages in a side-by-side arrangement adapted for dispensing of the same in a one-by-one fashion under gravity includes a flat elongated tubular body member (22), a lower end plug member (24), and an upper end plug member (26). The tubular body member has a first end and a second end. The tubular body member has a bore of a rectangular cross-section extending therethrough between the first end and the second end. The tubular body member includes a flat top wall portion (29), a flat bottom wall portion (30), and a pair of vertically extending side walls (32, 34) all formed integrally together. Opposed overhanging slot means (36) are formed in the pair of vertically extending side walls for supporting only two side edges of a plurality of BGA packages (12) so that top and bottom surfaces thereof are suspended freely between the top and bottom wall portions of the tubular body member. As a result, shock and potential physical damage to the BGA packages have been reduced during commercial handling and shipment.

Description: This invention relates to a BGA carrier of a unique construction for storing and shipping of ball grid array (BGA) packages in a side-by-side arrangement and adapted for dispensing of the same in a one-by-one fashion under gravity. In recent years, the miniaturization of integrated circuit chips has progressed significantly, and small-sized, rectangular plate-shaped parts of the type having no leads, such as pin grid array packages, have been coming into extensive use. Some of these types of pin grid array package structures are formed with solder balls on their bottom surface rather than with external terminal pins and are referred to as "ball grid arrays" (3GA) packages. BGA packages of this type have extraordinarily small outer dimensions. For example, a BGA package having 165 solder balls on its bottom surface may have dimensions of about 23.0 mm (in length) X 23.0 mm (in width) X 2.13 mm (in thickness). It is therefore quite difficult to store and/or transport a large number of these BGA packages in a predetermined arrangement. Moreover, it is extremely time-consuming to manually mount such BGA packages one-by-one onto a printed circuit board as is done in the case of conventional larger circuit components. As a result, there has arisen a need for chip carriers or containers for housing and/or shipping these BGA packages so as to facilitate their storage and transportation from an integrated circuit chip manufacturer's site to an assembly station at a customer's site where automatic equipment functions to remove the BGA packages from the chip carrier and to mount the BGA packages onto a printed circuit board (PCB) or the like. Further, the chip carrier may also function so as to bring different types of electrical components to the assembly station in proper order for sequential assembly operations. In order to function properly, the chip carriers must be capable of transporting the components placed therein and then, at the proper location (i.e., customer's site) be capable of being quickly and positively opened so that the components can be easily removed for assembly purposes. In addition, the chip carrier must also be able to provide a degree of protection for the sensitive components to be transported therein with respect to contamination, electrostatic discharge (ESD), temperature changes and mechanical shock. To date, the prior art solutions to these problems has involved the use of chip carrier trays having a plurality of separate compartments or pockets for holding the individual BGA packages apart from each other. For instance, there is shown in Figure 1 a chip carrier tray 2 of a generally rectangular configuration. The tray 2 includes a plurality of separate compartments 4 each adapted to hold a single BGA package 6. However, these prior art trays have the disadvantage of requiring a cover that is secured to the tray and to thereby prevent the components from prematurely falling out of the compartments. Further, the cover must be opened and reclosed for quality testing or the like and causes difficulties in alignment of the cover and the tray. In addition, the use of a tray type of chip carrier requires the need of an expensive "pick and place" mechanism to perform the functions of picking up the individual BGA packages from the separate compartments of the carrier tray and placing it in position for surface mounting on a printed circuit board or some other operation EP-A-0 470 920 discloses a prior art tube assembly for pin grid array modules in which ceramic pin grid array modules are carried on a strip with the pins of the modules protected in pin cavities or apertures in the carrying strip. Accordingly, we shall describe a BGA carrier of a tubular construction for storing and shipping of BGA packages in a side-by-side arrangement and adapted for dispensing of the same in a one-by-one fashion under gravity. The present invention provides a BGA carrier for storing and shipping of BGA packages in a side-by-side arrangement and adapted for dispensing of the same in a one-by-one fashion under gravity, said BGA carrier comprising: a flat, elongated tubular body member having a first end and a second end; said tubular member having a bore of a substantially rectangular cross-section extending therethrough between said first end and said second end; said tubular body member including a flat top wall portion, a flat bottom wall portion, and a pair of vertically extending side walls all formed integrally together; a plurality of BGA packages disposed in the bore of said tubular body member to substantially fill the same, each of said BGA packages being of a substantially rectangular shape and having side edges, a top surface, and a bottom surface; opposed slot means formed in said pair of vertically extending side walls and being arranged in the area intermediate said top and bottom wall portions; and said opposed slot means supporting only two of said side edges of said plurality of BGA packages so that the top and bottom surfaces thereof are suspended freely between said top and bottom wall portions of said tubular member. The carrier is relatively simple and economical to manufacture and assemble, but yet overcomes the disadvantages of the prior art carrier trays. It includes means for supporting only two side edges of the BGA package so that its top and bottom surfaces thereof are suspended freely in the tube, and means for guiding the BGA packages through the bore in a precise alignment so as to prevent a shingling effect. The BGA carrier may be made of an inexpensive material and construction, but yet is relatively durable and re-usable. In one embodiment, the carrier includes a flat, elongated tubular body, a lower end plug, and a upper end plug. The tubular body has a first end and a second end. The tubular body also includes a bore of a substantially rectangular cross-section extending therethrough between the first end and the second end. The tubular body is formed of a flat top wall portion. a flat bottom wall portion, and a pair of vertically extending side walls all joined integrally together. The lower end plug is disposed slidably and frictionally into the bore adjacent the first end of the tubular body. A plurality of BGA packages are disposed in the bore of the tubular body to substantially fill the same. Each of the BGA packages are of a substantially rectangular shape and has side edges, a top surface, and a bottom surface. In the embodiment, the pair of vertically extending side walls are formed with opposing overhanging slots which are arranged in the area intermediate the top and bottom wall portions. The opposed overhanging slots are used to support two of the side edges of the BGA package so that the top and bottom surfaces thereof are suspended freely between the top and bottom wall portions of the tubular member. The upper end plug member is disposed slidably and frictionally into the bore adjacent the second end of the tubular member. As a result, shock and potential physical damage to the BGA packages during commercial handling and shipping have been reduced. These and other objects and advantages of the present invention will become more fully apparent from the following detailed description when read in conjunction with the accompanying drawings with like reference numerals indicating corresponding parts throughout, wherein, by way of example only: Figure 1 is a perspective view of a chip carrier tray of the prior art; Figure 2 is a perspective view of a BGA carrier, constructed in accordance with the principles of the present invention; Figure 3 is a perspective view, similar to Figure 2, except with the end plug members and the BGA packages being removed; Figure 4 is a cross-sectional view, taken along the lines 4-4 of Figure 2; Figure 5 is an enlarged, perspective view of one of the plug members of Figure 2; and Figure 6 is a perspective view of a BGA package. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now in detail to the drawings, there is shown in Figure 2-4 a BGA carrier designated generally by reference numeral 10 and constructed in accordance with the principles of the present invention. The BGA carrier 10 is used to store and ship a plurality of ball grid array (BGA) packages 12 in a side-by-side arrangement and adapted for dispensing of the same in a one-by-one fashion under gravity, without the need of an expensive "pick and place" mechanism (not shown). Each of the BGA packages 12 (one of which is illustrated in detail in Figure 6) is of a substantially rectangular shape having side edges 14, a top surface 16, and a bottom surface 18. The bottom surface 18 is provided with a plurality of solder balls 20 arranged in a matrix arrangement. The BGA carrier 10 is comprised of a flat, elongated tubular body member 22, a lower end plug member 24, and an upper end plug member 26. The tubular body member 22 has a bore 28 of a substantially rectangular cross-section extending therethrough. The tubular body member is of a single-piece construction and is preferably formed of a suitable plastic film material such as polyvinyl chloride which may be readily extruded and vacuum or pressure formed to the desired shape. In addition, it should be appreciated by those skilled in the art that the plastic material can be formulated with an appropriate additive so as to render it anti-static or static dissipative as may be required. While the body member 22 may be of various dimensions, the side walls thereof are formed so as to conform to the contour of the BGA packages and the length thereof is such that a predetermined quantity of BGA packages can be stored or housed therein, for example, twenty. The body member includes a longitudinally extending flat top wall portion 29, a longitudinally extending flat bottom wall portion 30, and a pair of vertically extending side walls 32 and 34 all formed integrally together. In the illustrated embodiment, the top and bottom wall portions 29 and 30 have a length of approximately 508 mm and are spaced apart from each other by a distance of about 3.75 mm. Each of the side walls 32 and 34 includes an overhanging U-shaped slot 36 which is disposed in the area intermediate the top and bottom wall portions 29 and 30 and a rib-like member 38 extending outwardly from the slot 36. Each of the slots 36 define a continuous longitudinal recess which is coextensive in length with the top and bottom wall portions 29 and 30. As can be best seen from Figure 4, when the BGA packages are disposed in a side-by-side arrangement within the tubular member 22 only two peripheral edges of each BGA package are supported by means of the opposed overhanging slots 36 so that the top and bottom surfaces 16, 18 of the BGA package are suspended freely between the wall portions 29, 30 of the tubular member and thus the solder balls 20 do not contact or engage with any part of the tubular member. This serves to reduce the possibility of physical damage to the sensitive parts or bottom surface portions of the BGA package 12. Further, the interior surface 40 of the slots 36 are used to engage the respective side edges 14 of the BGA package and guides them through the bore 28 in a precise alignment so as to prevent the adjacent ones of the BGA packages from having a shingling effect where they tend to overlap one another. As a consequence, the BGA package can be supplied or dispensed in a uniformly smooth manner in a one-by-one fashion. As can be seen from Figure 5, there is shown an enlarged, perspective view of one of the end plug members 24 or 26 of Figure 2. Since the plug members 24 and 26 are identical in their construction, it will be sufficient to describe in detail only one of them. The plug member 24 (26) has a substantially T-shaped cross-section and is formed of a horizontal platform portion 42 and a narrow vertical portion 44 joined integrally to the platform portion 42. Each of the opposing sides of the vertical portion 44 is provided with a plurality of radially extending fin-like projections or tips 46 which elastically engages the inner surfaces of the bore 28 of the tubular member 22 and which serves to prevent the plug member from falling out due to their own weight. In this manner, each end of the tubular member 22 can be opened and closed so as to facilitate loading of the BGA packages 12 during production and to permit their subsequent removal by the customers. Each of the upper and lower end plug members 24, 26 is preferably fabricated from an elastomeric material such as rubber or other polymeric material. In use, the vertical portion 44 of the lower end plug member 24 is initially inserted into the bore 28 at the lower end or unloading (dispensing) end 48 of the tubular member 22. Then, pressure is applied to the platform portion 42 so as to cause the vertical portion 44 with its projections 46 to slide frictionally into the bore. A predetermined number of BGA packages 12 is loaded into the tubular member so as to completely fill the same, except for a small space at its upper or loading end 50. It will be noted that the distal end 51 of the vertical portion 44 of the lower end plug member 24 contacts or engages only the peripheral edge of the lowermost BGA package. Next, the upper end plug member 26 is inserted into the bore 28 at the loading end 50 of the tubular member 22 so that the distal end 52 of the vertical portion 44 thereof contacts or engages only the peripheral edge of the uppermost BGA package. Consequently, the loading end 50 of the tubular member is closed by the upper end plug member 26 so as to hold the BGA packages immovable in the tubular member 22 against undesirable free movement therein. Thus, shock and potential physical damage to the BGA packages 12 have been reduced during commercial handling and shipment. At the customer's site, the BGA carrier 10 is adapted to be vertically positioned or placed directly in a suitable processing machine so as to remove the BGA packages 12 from the tubular member 22 and to place them onto a printed circuit board under a gravity feed. As a result, the requirement of an expensive "pick and place" mechanism to perform this function when the prior art carrier trays are used have been eliminated. Therefore, the overall assembly operation can be simplified and the manufacturing cost is thus greatly reduced. It is also an important feature of the BGA carrier that after it has been complete unloaded the empty BGA carrier can be reused since it is made of a durable material. From the foregoing detailed description, it can thus be seen that the present invention provides an improved BGA carrier of a tubular construction for storing and shipping of BGA packages in a side-by-side arrangement and adapted for dispensing of the same in a one-by-one fashion under gravity. The BGA package of the present invention includes means for supporting only two peripheral edges of the BGA package so that its top and bottom surfaces are suspended freely between the top and bottom wall portions of a tubular member, thereby reducing the possibility of physical damage.

Claims: A ball grid array carrier for storing and shipping of ball grid array packages in a side-by-side arrangement and adapted for dispensing of the same in a one-by-one fashion under gravity, said ball grid array carrier comprising: a flat, elongated tubular body member (22) having a first end and a second end; said tubular member having a bore of a substantially rectangular cross-section extending therethrough between said first end and said second end; said tubular body member including a flat top wall portion (29), a flat bottom wall portion (30), and a pair of vertically extending side walls (32, 34) all formed integrally together; a plurality of ball grid array packages (12) disposed in the bore of said tubular body member to substantially fill the same, each of said ball grid array packages being of a substantially rectangular shape and having side edges, a top surface, and a bottom surface; opposed slot means (36) formed in said pair of vertically extending side walls and being arranged in the area intermediate said top and bottom wall portions; and said opposed slot means supporting only two of said side edges of said plurality of ball grid array packages so that the top and bottom surfaces thereof are suspended freely between said top and bottom wall portions of said tubular member. A ball grid array carrier as claimed in claim 1, wherein said slot means includes interior surfaces (40) which engage the respective side edges of the plurality of ball grid array packages and guides the same to the bore in a precise alignment so as to prevent a shingling effect. A ball grid array carrier as claimed in claim 1, wherein; said first end of said elongated tubular body member (22) is a dispensing end and said second end of said elongated tubular body member (22) is a loading end; said ball grid array carrier further comprising: first plug means (24) disposed slidably and frictionally into the bore adjacent said dispensing end of said tubular member, and second plug means (26) disposed slidably and frictionally into the bore adjacent said second end of said tubular member. A ball grid array carrier as claimed in claim 3, wherein said tubular body member is formed of a plastic film material. A ball grid array carrier as claimed in claim 3, wherein said tubular body member is formed of polyvinyl chloride. A ball grid array carrier as claimed in claim 3, wherein each of said first and second plug means are formed of an elastomeric material. A ball grid array carrier as claimed in claim 3, wherein each of said first and second plug means has a substantially T-shaped cross-section and includes a horizontal platform portion (42) and a narrow vertical portion (44) joined integrally to said platform portion. A ball grid array carrier as claimed in claim 7, wherein said vertical portions of said plug means are provided with fin-like projections (46) which elastically engages the inner surfaces of the bore of said tubular member. A ball grid array carrier as claimed in claim 3, wherein each of said opposed slot means includes an interior surface (40) which engages the respective side edges of the plurality of ball grid array packages and guides the same through the bore in a precise alignment so as to prevent a shingling effect. A ball grid array carrier as claimed in claim 8, wherein said vertical portion of said first plug means has a distal end (51) which engages one of the remaining side edges of the lowermost ball grid array package. A ball grid array carrier as claimed in claim 10, wherein said vertical portion of said second plug means has a distal portion (52) which engages one of the remaining side edges of the uppermost ball grid array package. A ball grid array carrier as claimed in any one of claims 3 to 11, wherein said first plug means comprises a lower end plug member and said second plug means comprises an upper end plug member.

Inventors: GHANI MOKHTAR, HOSSEINMARDI MOHSEN, PAKERIASAMY SARAGARVANI, GHANI, MOKHTAR, HOSSEINMARDI, MOHSEN, PAKERIASAMY, SARAGARVANI
Applicants: ADVANCED MICRO DEVICES INC, ADVANCED MICRO DEVICES INC.
Application year: 1994
Main classification: H05K13
IPC codes: H05K13, H01L23, B65D85